High Resolution Chronostratigraphic Constraints on Terminal Paleozoic Crises and Recovery in the Circum-Tethys Region

高分辨率年代地层对环特提斯地区古生代末期危机和恢复的制约

• 批准号: 0125799
• 负责人: Roland Mundil
• 金额: $ 28.51万
• 依托单位: Berkeley Geochronology Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125799&HistoricalAwards=false
• 关键词: Resolution; Chronostratigraphic; Constraints; Terminal; Paleozoic

ABSTRACTHigh Resolution Chronostratigraphic Constraints on Terminal Paleozoic Crises and Recovery in the Circum-Tethys RegionRoland Mundil, Kenneth R. Ludwig, Paul R. RenneThis research program is intended to improve the calibration of late Permian through Triassic biostratigraphic and magnetostratigraphic time scales towards an enhanced understanding of the terminal Paleozoic environmental and biotic crisis and subsequent Mesozoic recovery. Improved time scales are critical to realistic evaluation of the causes of, and interrelationships between, the various observed biotic and paleoenvironmental anomalies that characterize this transition. Our initial radio-isotopic age data (both U/Pb and Ar/Ar) are at variance with recent studies, many of which favor a rapid extinction caused by a bolide impact. Although an impact at or near the P-T boundary cannot be excluded a priori, a more gradual scenario and a causal relation between the massive continental basalt volcanism in South China at the end of the Permian and Siberia at the Permian-Triassic boundary - possibly in combination with other factors - and the biotic crisis must be considered. Despite the dramatic increase in available geochronologic data for the Late Permian through Early Triassic interval, crucial questions remain unanswered and will be addressed: 1) How synchronous are global biostratigraphic correlations across the Permo-Triassic boundary, and how precisely can biostratigraphic, geochemical, lithostratigraphic, and other records be correlated? 2) What are the temporal relations between terrestrial and marine records across the Permo-Triassic boundary? 3) What was the rate of the biotic recovery in the Early Triassic? 4) Do interlaboratory discrepancies (either physical or by interpretation) between high-precision U/Pb zircon ages for the Permo-Triassic boundary undermine the inferred extremely rapid chronology of extinction events? Indeed, how reliable is U/Pb zircon geochronology as a Phanerozoic time scale method?

摘要：高分辨率年代地层对环特提斯地区古生代末期危机和恢复的限制Roland Mundil、Kenneth R. Ludwig、Paul R. Renne 该研究项目旨在通过三叠纪生物地层和磁性地层时间尺度改进对晚二叠世的校准，以增强对古生代末期环境和生物危机和恢复的认识。 随后的中生代恢复。改进的时间尺度对于现实评估表征这一转变的各种观察到的生物和古环境异常的原因以及之间的相互关系至关重要。我们最初的放射性同位素年龄数据（U/Pb 和 Ar/Ar）与最近的研究不一致，其中许多研究支持火流星撞击导致的快速灭绝。尽管不能先验地排除P-T边界处或附近的影响，但必须考虑二叠纪末华南和二叠纪-三叠纪边界西伯利亚的大规模大陆玄武岩火山活动与生物危机之间的更为渐进的情况和因果关系（可能与其他因素相结合）。尽管二叠纪晚期到三叠纪早期的可用地质年代学数据急剧增加，但关键问题仍然悬而未决，并将得到解决：1）二叠纪-三叠纪边界上的全球生物地层相关性如何同步，以及生物地层、地球化学、岩石地层和其他记录之间的相关性如何精确？ 2）二叠纪-三叠纪边界的陆地和海洋记录之间的时间关系是什么？ 3）早三叠世生物恢复速度是多少？ 4) 二叠纪-三叠纪边界的高精度 U/Pb 锆石年龄之间的实验室间差异（无论是物理的还是解释的）是否会破坏推断的极快的灭绝事件年表？事实上，U/Pb 锆石地质年代学作为显生宙时间尺度方法的可靠性如何？